I'm not sure how accurate all of this is in accordance to laws, but this may be of some help:

http://www.erowid.org/freedom/police...consent1.shtml

It talks about saying no to police and such. The page just before that is this one:

http://www.erowid.org/freedom/freedom.shtml

which should give you even more insight to your rights. However, I really have to state again I'm not sure how accurate all of this information is, but if you're scared, this may be a good place to start.